This invention relates to method of combating undesired plant growth using certain 2-alkynyl-pyri(mi)dines, to novel 2-alkynyl-pyri(mi)dines, to the preparation of these compounds, and to herbicidal compositions containing such compounds.
Pyridines, pyrimidines and their derivatives have many uses in the pharmaceutical area as well as in agriculture (herbicides, fungicides, acaricides, anthelmintics, bird repellents), as reagents, intermediates and chemicals for the polymer and textile industry.
The German patent application DE 40 29 654 discloses fungicidal 2-phenyl-4-alkynyloxy-pyrimidines. However, there is no hint to 2-alkynyl-pyrimidines nor any motivation that such compounds could show herbicidal activity.
The French patent application FR 2 605 010 describes polymers obtainable by thermal polymerization of bis-(2-ethynyl-pyrid-6-yloxy)-arenes. There is no hint that those oligomers could exhibit any herbicidal activity at all.
The compounds according to the present invention combine high herbicidal activity with good selectivity and a desirable rate of degradation in soil.